Methods for lte channel selection in unlicensed bands

ABSTRACT

Described herein are techniques for reducing interference to non-cellular communications on an unlicensed band by a network entity sending/receiving cellular communications on the unlicensed band. For example, the technique may involve operating in a first mode using a first radio access technology (RAT1), and collecting interference measurements for interference to or from at least one mobile device while in the first mode. The technique may also involve switching to a second mode and using a second radio access technology (RAT2), and using the interference measurements from the first mode to minimize interference caused or experienced by the network entity in the second mode.

BACKGROUND

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to reducing interferenceto non-cellular communications on unlicensed bands.

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, etc. These wireless networks may be multiple-access networkscapable of supporting multiple users by sharing the available networkresources. Examples of such multiple-access networks include CodeDivision Multiple Access (CDMA) networks, Time Division Multiple Access(TDMA) networks, Frequency Division Multiple Access (FDMA) networks,Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA)networks.

A wireless communication network may include a number of networkentities, such as base stations, that can support communication for anumber of mobile entities/devices, such as, for example, user equipment(UE) or access terminals (ATs). A mobile device may communicate with abase station via a downlink and uplink. The downlink (or forward link)refers to the communication link from the base station to the UE, andthe uplink (or reverse link) refers to the communication link from theUE to the base station.

The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)represents a major advance in cellular technology as an evolution ofGlobal System for Mobile communications (GSM) and Universal MobileTelecommunications System (UMTS). The LTE physical layer (PHY) providesa highly efficient way to convey both data and control informationbetween a base station, such as an evolved Node B (eNB), and a mobiledevice, such as a UE.

With the increased deployment of neighborhood small cells (NSCs), suchas, for example, femto cells or similar small cells, there will be anincreased demand for the licensed spectrum, which will likely result inspectrum shortages. Deploying NSCs on the unlicensed spectrum (e.g., 5GHz) can unleash huge potential in meeting increased spectrum demands.It is further noted that LTE can provide higher spectral efficiency ascompared to IEEE 802.11 (Wi-Fi) in the unlicensed spectrum. However, thedeployment of NCSs on the unlicensed spectrum may result in interferenceto non-cellular communications on the unlicensed band. In this context,there remains a need for techniques to reduce interference by NSCsdeployed on unlicensed bands.

SUMMARY

Illustrative aspects of the present disclosure that are shown in thedrawings are summarized below. These and other aspects are more fullydescribed in the detailed description section. It is to be understood,however, that the disclosure is not limited to the forms described inthis Summary or in the detailed description.

In accordance with one or more aspects described herein, there isprovided a method for interference management operable by a networkentity (e.g., an NSC) or component(s) thereof. The method may involveoperating in a first mode using a first radio access technology (RAT1).The method may involve collecting interference measurements forinterference to or from at least one mobile device while in the firstmode. The method may further involve switching to a second mode andusing a second radio access technology (RAT2). The method may alsoinvolve using the interference measurements from the first mode tominimize interference caused or experienced by the network entity in thesecond mode.

In related aspects, the method may involve collecting the interferencemeasurements in the first mode by using Wi-Fi over 802.11k. In furtherrelated aspects, the method may involve collecting the interferencemeasurements in the first mode by using LTE by modifying ReferenceSignal Received Power (RSRP)/Reference Signal Received Quality (RSRQ).

In yet further related aspects, the method may involve building adatabase from the collected interference measurements, the databasecomprising information regarding interference levels experienced by thenetwork entity for LTE communication on channels of the unlicensed band,and selecting and communicating on a selected channel of the unlicensedband to minimize the interference caused or experienced by the networkentity

In still further related aspects, the method may involve defining aninterference criteria based at least in part on a received signalstrength indicator (RSSI) metric or a duty cycle metric, and selectingthe selected channel in response to selected channel satisfying theinterference criteria. In other related aspects, an electronic device(e.g., an NSC, a UE or component(s) thereof) may be configured toexecute the above described methodology.

To the accomplishment of the foregoing and related ends, the one or moreimplementations include the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspects ofthe one or more implementations. These aspects are indicative, however,of but a few of the various ways in which the principles of variousimplementations may be employed and the described implementations areintended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram conceptually illustrating an example of atelecommunications system.

FIG. 1B shows an example dual-capability base station.

FIG. 1C illustrates a scenario in an unlicensed spectrum resulting ininterference at an LTE-U (LTE operating in unlicensed band) SC (smallcell).

FIG. 1D illustrates a scenario in an unlicensed spectrum resulting ininterference at a UE.

FIG. 2 is a block diagram conceptually illustrating a design of a basestation and a UE configured according to one aspect of the presentdisclosure.

FIG. 3 illustrates an example methodology for interference management toreduce interference to non-cellular communications on an unlicensedspectrum.

FIGS. 4A-B illustrate further examples or aspects of methodologies forchannel selection.

FIG. 5 shows an example apparatus for implementing the method of FIGS.3-4B.

DETAILED DESCRIPTION

The present disclosure relates to techniques for reducing interferenceto non-cellular communications (e.g., wireless local area network (WLAN)communications) on an unlicensed band by a network entity (e.g., aneighborhood small cell (NSC) sending/receiving cellular communicationson the unlicensed band. NSCs provide an alternative to deploying macrobase stations to provide increased cellular coverage. However, a majorroadblock for wide NSC deployment is the lack of available spectrum onlicensed bands. Deploying NSCs on unlicensed bands holds great potentialfor increasing cellular coverage. It is noted that certain cellularprotocols, such as LTE, provides higher spectral efficiency and coveragecompared to non-cellular or WLAN protocols, such as Wi-Fi. However, thedeployment of NSCs in the unlicensed bands may disrupt or causeinterference to non-cellular (e.g., Wi-Fi) communications on theunlicensed bands.

In one example, there is provided a network entity (e.g., a small basestation) that includes a NSC co-located with a WLAN access point (AP).The co-located WLAN AP may query measurements from all associated mobiledevices on other channels using the 802.11k framework or the like. Themobile devices may modify Reference Signal Received Power(RSRP)/Reference Signal Received Quality (RSRQ) inter-frequencymeasurements based on actual Wi-Fi interference measured.

It is noted that the detailed description set forth below, in connectionwith the appended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. However, it will beapparent to those skilled in the art that these concepts may bepracticed without these specific details. In some instances, well-knownstructures and components are shown in block diagram form in order toavoid obscuring such concepts.

It is further noted that the techniques described herein may be used forvarious wireless communication networks such as CDMA, TDMA, FDMA, OFDMA,SC-FDMA and other networks. The terms “network” and “system” are oftenused interchangeably. A CDMA network may implement a radio technologysuch as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRAincludes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA2000covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implementa radio technology such as Global System for Mobile Communications(GSM). An OFDMA network may implement a radio technology such as EvolvedUTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are partof Universal Mobile Telecommunication System (UMTS). 3GPP LTE andLTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA,E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). CDMA2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). The techniques describedherein may be used for the wireless networks and radio technologiesmentioned above as well as other wireless networks and radiotechnologies. For clarity, certain aspects of the techniques aredescribed below for LTE, and LTE terminology is used in much of thedescription below.

FIG. 1A shows an example wireless communication network 100, which maybe an LTE network or the like. The wireless network 100 may include anumber of base stations 110 (e.g., evolved Node Bs (eNBs), NSCs, etc.)and other network entities. A base station may be a station thatcommunicates with the UEs and may also be referred to as a Node B, anAP, or other term. Each eNB 110 a, 110 b, 110 c may providecommunication coverage for a particular geographic area. In 3GPP, theterm “cell” can refer to a coverage area of an eNB and/or an eNBsubsystem serving this coverage area, depending on the context in whichthe term is used.

An eNB may provide communication coverage for a macro cell, a pico cell,a femto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG), UEs for users in the home,etc.). It is noted that a pico cell and a femto cell are examples ofNSCs.

An eNB for a macro cell may be referred to as a macro eNB. An eNB for apico cell may be referred to as a pico eNB. An eNB for a NSC may bereferred to as a NSC eNB or a home eNB (HNB). In the example shown inFIG. 1, the eNBs 110 a, 110 b and 110 c may be macro eNBs for the macrocells 102 a, 102 b and 102 c, respectively.

The eNB 110 x may be a NSC eNB for a NSC 102 x, serving a UE 120 x. Inthe present example, eNB 110 x operates in licensed bands, as do theeNBs 110 a, 110 b and 110 c. In contrast, a base station 112 operates inan unlicensed band, and includes both a NSC eNB module for a NSC 103 anda WLAN AP module to provide Wi-Fi coverage in a service area 105. Thedual-capability base station 112 may serve a UE 125 that is configuredto operate in the unlicensed band, either via the NSC 103 or via Wi-Fi,assuming the UE 125 is within the coverage area 105 and configured forWi-Fi (i.e., includes a Wi-Fi radio module).

An example dual-capability base station 112 is shown in FIG. 1B. Forexample, a NSC radio module 130 and a WLAN radio module 140 may beco-located.

The base station 112 may optionally include a controller module 113 inoperative communication with the NSC radio module 130 and the WLAN radiomodule 140 to coordinate the activity of the modules 130, 140 and/orcomponents thereof.

In related aspects, the NSC radio module 130 may include a transmitter(TX) component 132, a receiver (RX) component 134, a processor component136, and a interference measurement component 138, wherein each of thecomponents are in operative communication with each other. Theinterference measurement component 138 may collect or coordinatecollecting interference measurements for interference to or from atleast one mobile device, and may include a database of collectedinterference measurements.

The NSC radio module 130 may include one or more of the components ofbase station 110 shown on the left hand side of FIG. 2. The WLAN radiomodule 140 may include a TX component 142, a RX component 144, and aprocessor component 146, wherein each of the components are in operativecommunication with each other. In further related aspects, one or moreof the components 132-138 may be configured to collect interferencemeasurements when the WLAN radio module 140 is activated. In yet furtherrelated aspects, one or more of the components 142-146 may be configuredto minimize interference caused or experienced by the base station whilethe WLAN radio module 140 is activated, according to the exemplarymethodologies shown in FIGS. 3-4B, and described in further detailbelow.

The base station 112 may initially operate as the WLAN AP and collectinterference measurements from mobile devices communicating on channelsof the unlicensed band. The base station 112 may build a database fromthe collected interference measurements, and may share information inthe database with other small base stations over x2 links or the like.Alternatively or additionally, a centralized controller may collect suchinformation from the base stations (e.g., small cells), along with thebase station locations, and make/send a feedback decision for channelselection to each base station. For example, the base station 112 maythen operate as an LTE small cell in an unlicensed band and use theinformation in the database to select and communicate on a given channelof the unlicensed band to minimize interference caused or experienced bythe base station 112.

With reference once again to FIG. 1A, the network 100 may also include aan LTE-U (LTE operating in unlicensed band) small cell (SC) 115 that isco-located with a Wi-Fi AP radio or the like. The LTE-U SC 115 operatesin the unlicensed band provides Wi-Fi coverage in a service area 104.The LTE-U SC 115 may provide Wi-Fi service for a UE 125 that is withinthe coverage area 104 and configured for Wi-Fi (i.e., includes a Wi-Firadio module). The UE 125 may be in the in operative communication witha small cell (e.g., a femto cell or a pico cell) in an unlicensed band103 and in the coverage area 104 simultaneously, and may be capable ofboth cellular and non-cellular communication in the unlicensed band.

A network controller 130 may couple to a set of eNBs and providecoordination and control for these eNBs. The network controller 130 maycommunicate with the eNBs 110 via a backhaul. The eNBs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 may be dispersed throughout the wireless network 100, andeach UE may be stationary or mobile. A UE may also be referred to as aterminal, a mobile station, a subscriber unit, a station, etc. A UE maybe a cellular phone, a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, orother mobile devices. In FIG. 1A, a solid line with double arrowsindicates desired transmissions between a UE and a serving eNB, which isan eNB designated to serve the UE on the downlink and/or uplink. Adashed line with double arrows indicates interfering transmissionsbetween a UE and an eNB.

Interference at the LTE-U SC: With reference to FIG. 1C, within anunlicensed band 150, a Wi-Fi device (e.g. AP 156 or STA 158) may behidden from a UE 152 and may interfere with LTE-U uplink (UL)communications with a LTE-U SC 154. Such a scenario would impact PUSCHperformance, such as, for example, the PUCCH/PRACH sent on a primarycomponent carrier (PCC). The PUCCH/PRACH may be sent on the PCC to avoidinterference issues.

Interference at the UE: With reference to FIG. 1D, within an unlicensedband 160, a Wi-Fi device (e.g., AP 166 or STA 168) may be hidden from aLTE-U SC 162 and may interfere with LTE-U downlink (DL) communicationswith a UE 164. Such interference (INTF) to LTE-U downlink communicationsmay impact the primary synchronization signal (PSS)/secondarysynchronization signal (SSS), thereby affecting synchronizationgenerally. Averaging can help reduce the impact to synchronization, andsince is PSS/SSS is narrowband, the small cell in the unlicensed bandmay boost its power as needed. Interference to LTE-U downlinkcommunications may impact PDCCH performance. Cross-carrier schedulingmay be implemented to send grants on the PCC; similarly, PBCH may besent on the PCC for robustness. Interference to Wi-Fi downlinkcommunications may impact PDSCH performance, may impact measurements(e.g., RSRP/RSRQ can be corrupted and/or not reflect Wi-Fi interferencecorrectly), and may result in channel quality indication (CQI) mismatchgiven that the cell-specific reference signal (CRS) may not capture allWi-Fi interference.

LTE-U Channel Selection: In one approach LTE-U channel selection, anetwork entity (e.g., an LTE small cell in an unlicensed band or thelike) may perform network listen to measure the interference level andduty cycle on different channels from both LTE-U and Wi-Fi networks. Inone approach, this may involve taking RSSI measurements over each OFDMsymbol and calculating order statistics based on the RSSI measurements.Assistance from co-located AP measurements may be specific for Wi-Fisignals (e.g., beacons, measuring RSSI from PLCP headers, etc.). Networklisten may be performed periodically or triggered based on highuplink/downlink PER, IoT pattern, CQI pattern, CQI back-off, or thelike. In related aspects, the PCC may configure the best availableSCC(s) each trigger or channel selection period. While this approachaddresses interference at the small cell in an unlicensed band, it doesnot address interference experienced at the UE.

In another approach to LTE-U channel selection, the network entity mayutilize co-channel UE measurements and channel state information (CSI)reports. This may involve combining metrics, such as, for example, theCQI pattern, the reference signal received quality (RSRQ), and/or therate control outer loop back-off to deduce co-channel quality andtrigger channel selection. It is noted, however, that inter-frequency UEmeasurements such as RSRP/RSRQ may not capture Wi-Fi interference onother channels. In related aspects, the small cells in an unlicensedbands may exchange information about the quality of the channels over X2links or the like.

In yet another approach to LTE-U channel selection, the network entitymay rely on interference diversity provided by using multiple SCCs, suchas, for example, PCC, SCC1, SCC2, . . . , SCCk, or the like. The SCCsmay be selected based on the network listen management (NLM) or thelike. A given UE may be served on all available SCCs if it does notdetect any Wi-Fi interference. The given UE would not be scheduled onthose SCCs determined to experience Wi-Fi interference levels meeting orexceeding a given interference threshold, such as a system-definedvalue. For example, the determination may be based at least in part on achannel quality indicator (CQI), rate control outer loop back off, orthe like. In one example, two SCCs may be sufficient for interferencediversity given the low probability that a given UE would have strongWi-Fi jammers on both channels associated with the two SCCs.

In related aspects, a given SC may schedule a narrower PDSCH to increaserobustness, which may help reduce the impact from adjacent channelinterference or the like. However, there are restrictive power spectraldensity limits for Unlicensed National Information Infrastructure(UNIT)—low power or the like.

In yet another approach to LTE-U channel selection, the network entitymay measure the Wi-Fi beacon signal strength and/or the trainingsequence RSSI, and de-prioritize channel selection (i.e., avoid certainWi-Fi channels) that can cause high interference to Wi-Fi.

One approach to reducing or minimizing interference to such non-cellularcommunications is to implement a channel selection technique that keepsthe small cells in an unlicensed band concentrated on a few channels onthe unlicensed band. Still, there remains a need for an improved channelselection technique for reducing interference caused to non-cellularcommunications in the unlicensed band.

Such a channel selection technique may involve defining a list ofchannels with priority. The small cell may go through each channel inthe order of priority and pick the one which satisfies an interferencecriteria, such as, for example, a received signal strength indicator(RSSI) being lower than a threshold. In another example, theinterference criteria may be a metric that combines RSSI and duty cycleof interference, wherein the metric is below than another definedthreshold. It is noted that, in one example, if the rate control loop istargeting 10% block error rate (BLER) on a first transmission, then evena jammer with a 10% duty cycle can impact the performance.

If no channels satisfy the criteria, then the small cell may pick thechannel with least interference. The small cell may further distinguishbetween Wi-Fi contribution to the RSSI and LTE contribution to the RSSI,such as, for example, by detecting the physical layer convergenceprotocol (PLCP) header of Wi-Fi packets or Wi-Fi beacons. The RSSIcontribution from Wi-Fi may be given higher weight than LTE (i.e., itmay be preferable to select a co-channel with LTE to leverage existinginterference management). A WiFi basic service set (BSS) with a serviceset identifier (SSID) belonging to the same operator/user can be furthergiven higher weight to be avoided (through decoding the beacon).Neighbor small cells may exchange measurements on the channel list overX2 or the like.

FIG. 2 shows a block diagram of a design of a base station 110 and a UE120, which may be one of the base stations (e.g., an NSB such as 110 x,110 y, or 110 z) and one of the UEs, respectively, in FIG. 1. The basestation 110 may be equipped with antennas 234 a through 234 t, and theUE 120 may be equipped with antennas 252 a through 252 r.

At the base station 110, a transmit processor 220 may receive data froma data source 212 and control information from a controller/processor240. The control information may be for the PBCH, PCFICH, PHICH, PDCCH,etc. The data may be for the PDSCH, etc. The processor 220 may process(e.g., encode and symbol map) the data and control information to obtaindata symbols and control symbols, respectively. The processor 220 mayalso generate reference symbols, e.g., for the PSS, SSS, andcell-specific reference signal. A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, and/or thereference symbols, if applicable, and may provide output symbol streamsto the modulators (MODs) 232 a through 232 t. Each modulator 232 mayprocess a respective output symbol stream (e.g., for OFDM, etc.) toobtain an output sample stream. Each modulator 232 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. Downlink signals frommodulators 232 a through 232 t may be transmitted via the antennas 234 athrough 234 t, respectively.

At the UE 120, the antennas 252 a through 252 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 254 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all the demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 120 to a data sink 260, and provide decoded control informationto a controller/processor 280.

On the uplink, at the UE 120, a transmit processor 264 may receive andprocess data (e.g., for the PUSCH) from a data source 262 and controlinformation (e.g., for the PUCCH) from the controller/processor 280. Theprocessor 264 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 264 may be precoded by aTX MIMO processor 266 if applicable, further processed by the modulators254 a through 254 r (e.g., for SC-FDM, etc.), and transmitted to thebase station 110. At the base station 110, the uplink signals from theUE 120 may be received by the antennas 234, processed by thedemodulators 232, detected by a MIMO detector 236 if applicable, andfurther processed by a receive processor 238 to obtain decoded data andcontrol information sent by the UE 120. The processor 238 may providethe decoded data to a data sink 239 and the decoded control informationto the controller/processor 240.

The controllers/processors 240 and 280 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 240 and/orother processors and modules at the base station 110 may perform ordirect the execution of various processes for the techniques describedherein. The processor 280 and/or other processors and modules at the UE120 may also perform or direct the execution of the functional blocksillustrated in FIGS. 6 and 7, and/or other processes for the techniquesdescribed herein. The memories 242 and 282 may store data and programcodes for the base station 110 and the UE 120, respectively. A scheduler244 may schedule UEs for data transmission on the downlink and/oruplink.

In one configuration, the base station 110 and/or the UE 120 may includemeans for performing the process illustrated in FIGS. 3-4. In oneexample, the aforementioned means may be the processor(s), thecontroller/processor 280, the memory 282, the receive processor 258, theMIMO detector 256, the demodulators 254 a, and the antennas 252 aconfigured to perform the functions recited by the aforementioned means.In another aspect, the aforementioned means may be a module or anyapparatus configured to perform the functions recited by theaforementioned means.

In view of exemplary systems shown and described herein, methodologiesthat may be implemented in accordance with the disclosed subject matter,will be better appreciated with reference to various flow charts. While,for purposes of simplicity of explanation, methodologies are shown anddescribed as a series of acts/blocks, it is to be understood andappreciated that the claimed subject matter is not limited by the numberor order of blocks, as some blocks may occur in different orders and/orat substantially the same time with other blocks from what is depictedand described herein. Moreover, not all illustrated blocks may berequired to implement methodologies described herein. It is to beappreciated that functionality associated with blocks may be implementedby software, hardware, a combination thereof or any other suitable means(e.g., device, system, process, or component). Additionally, it shouldbe further appreciated that methodologies disclosed throughout thisspecification are capable of being stored on an article of manufactureto facilitate transporting and transferring such methodologies tovarious devices. Those skilled in the art will understand and appreciatethat a methodology could alternatively be represented as a series ofinterrelated states or events, such as in a state diagram.

With reference to FIG. 3, illustrated is a methodology 300 that may beperformed at a network entity, such as, for example, the dual-capabilitybase station 112 as shown in FIGS. 1A-B. The method 300 may involve, at310, operating in a first mode using a first radio access technology(RAT1). The method 300 may involve, at 320, collecting interferencemeasurements for interference to or from at least one mobile devicewhile in the first mode. The method 300 may involve, at 330, switchingto a second mode and using a second radio access technology (RAT2). Themethod 300 may involve, at 340, using the interference measurements fromthe first mode to minimize interference caused or experienced by thenetwork entity in the second mode.

With reference to FIGS. 4A-B, there are shown further operations oraspects of method 300 that are optional are not required to perform themethod 300. If the method 300 includes at least one block of FIG. 4-B,then the method 300 may terminate after the at least one block, withoutnecessarily having to include any subsequent downstream block(s) thatmay be illustrated. For example, collecting the interferencemeasurements in the first mode (block 320) may involve using Wi-Fi over802.11k (block 350).

In related aspects, collecting the interference measurements in thefirst mode (block 320) may involve using LTE by modifying ReferenceSignal Received Power (RSRP)/Reference Signal Received Quality (RSRQ)(block 360).

In yet further related aspects, the method 300 may involve building adatabase from the collected interference measurements, the databasecomprising information regarding interference levels experienced by thenetwork entity for LTE communication on channels of the unlicensed band(block 370).

The method 300 may involve selecting and communicating on a selectedchannel of the unlicensed band to minimize the interference caused orexperienced by the network entity (block 372). The method 300 mayinvolve: defining an interference criteria based at least in part on anRSSI metric or a duty cycle metric (block 374); and selecting theselected channel, in response to selected channel satisfying theinterference criteria (block 376).

In still further related aspects, operating in the first mode (block310) may involve communicating via Wi-Fi on the unlicensed band (block380), while operating in the second mode (blocks 330 and/or 340) mayinvolve communicating with one or more of the mobile devices on theunlicensed channel via LTE (block 382).

In further related aspects, collecting the interference measurements(block 320) may involve directly making the interference measurements(block 390), and/or collecting the interference measurements comprisesreceiving the interference measurements from one or more of the mobiledevices (block 392).

In one example, wherein the network entity comprises an LTE small cellin an unlicensed band or the like, one or more of blocks 310-392 may beperformed by the controller/processor 240, the memory 242, the scheduler244, the receive processor 238, and/or the transmit processor 220 of thebase station 110, as shown in FIG. 2. In another example, wherein thenetwork entity comprises a dual-capability base station, one or more ofblocks 310-392 may be performed by the NSC radio module 130, the WLANradio module 140, or component(s) thereof, shown in FIG. 1B.

With reference to FIG. 5, there is provided an exemplary apparatus 500that may be configured as a UE, network entity, or other suitableentity, or as a processor, component or similar device for use withinthe UE, network entity, or other suitable entity, for network nodeselection. The apparatus 500 may include functional blocks that canrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware).

As illustrated, in one example, the apparatus 500 may include anelectrical component or module 502 for operating in a first mode using aRAT1. The apparatus 500 may include an electrical component or module504 for collecting interference measurements for interference to or fromat least one mobile device while in the first mode. The apparatus 500may include an electrical component or module 506 for switching to asecond mode and using a RAT2. The apparatus 500 may include anelectrical component or module 508 for using the interferencemeasurements from the first mode to minimize interference caused orexperienced by the network entity in the second mode.

In related aspects, the apparatus 500 may optionally include a processorcomponent 510 having at least one processor, in the case of theapparatus 500 configured as a network entity. The processor 510, in suchcase, may be in operative communication with the components 502-508 orsimilar components via a bus 512 or similar communication coupling. Theprocessor 510 may effect initiation and scheduling of the processes orfunctions performed by electrical components or modules 502-508.

In further related aspects, the apparatus 500 may include a networkinterface component 514 for communicating with other network entities.The apparatus 500 may optionally include a component for storinginformation, such as, for example, a memory device/component 516. Thecomputer readable medium or the memory component 516 may be operativelycoupled to the other components of the apparatus 500 via the bus 512 orthe like. The memory component 516 may be adapted to store computerreadable instructions and data for performing the activity of thecomponents 502-508, and subcomponents thereof, or the processor 510. Thememory component 516 may retain instructions for executing functionsassociated with the components 502-508. While shown as being external tothe memory 516, it is to be understood that the components 502-508 canexist within the memory 516.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection may be properly termed acomputer-readable medium to the extent involving non-transient storageof transmitted signals. For example, if the software is transmitted froma website, server, or other remote source using a coaxial cable, fiberoptic cable, twisted pair, digital subscriber line (DSL), or wirelesstechnologies such as infrared, radio, and microwave, then the coaxialcable, fiber optic cable, twisted pair, DSL, or wireless technologiessuch as infrared, radio, and microwave are included in the definition ofmedium, to the extent the signal is retained in the transmission chainon a storage medium or device memory for any non-transient length oftime. Disk and disc, as used herein, includes compact disc (CD), laserdisc, optical disc, digital versatile disc (DVD), floppy disk andblu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveshould also be included within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method operable by a network entity configuredfor wireless communication, the method comprising: operating in a firstmode using a first radio access technology (RAT1); collectinginterference measurements for interference to or from at least onemobile device while in the first mode; switching to a second mode andusing a second radio access technology (RAT2); and using theinterference measurements from the first mode to minimize interferencecaused or experienced by the network entity in the second mode.
 2. Themethod of claim 1, wherein collecting the interference measurements inthe first mode comprises using Wi-Fi over 802.11k.
 3. The method ofclaim 1, wherein collecting the interference measurements in the firstmode comprises using Long Term Evolution (LTE) by modifying ReferenceSignal Received Power (RSRP)/Reference Signal Received Quality (RSRQ).4. The method of claim 1, further comprising building a database fromthe collected interference measurements, the database comprisinginformation regarding interference levels experienced by the networkentity for LTE communication on channels of the unlicensed band.
 5. Themethod of claim 4, further comprising selecting and communicating on aselected channel of the unlicensed band to minimize the interferencecaused or experienced by the network entity.
 6. The method of claim 5,further comprising: defining an interference criteria based at least inpart on a received signal strength indicator (RSSI) metric or a dutycycle metric; and selecting the selected channel, in response toselected channel satisfying the interference criteria.
 7. The method ofclaim 4, wherein: operating in the first mode comprises communicatingvia Wi-Fi on the unlicensed band; and operating in the second modecomprises communicating with one or more of the mobile devices on theunlicensed channel via LTE.
 8. The method of claim 4, wherein collectingthe interference measurements comprises (a) directly making theinterference measurements or (b) collecting the interferencemeasurements comprises receiving the interference measurements from oneor more of the mobile devices.
 9. The method of claim 1, wherein theinterference measurements are based at least in part on an RSSI.
 10. Themethod of claim 1 wherein the network entity comprises a small basestation that includes a neighborhood small cell (NSC) co-located with aWi-Fi access point.
 11. The method of claim 1, wherein the networkentity is configured to (a) operate in a standalone unlicensed band or(b) operate in both a licensed band and the unlicensed band in a carrieraggregation mode.
 12. An apparatus, comprising: means for operating in afirst mode using a first radio access technology (RAT1); means forcollecting interference measurements for interference to or from atleast one mobile device while in the first mode; means for switching toa second mode and using a second radio access technology (RAT2); andmeans for using the interference measurements from the first mode tominimize interference caused or experienced by the network entity in thesecond mode.
 13. The apparatus of claim 12, further comprising means formodifying Reference Signal Received Power (RSRP)/Reference SignalReceived Quality (RSRQ).
 14. The apparatus of claim 12, furthercomprising means for building a database from the collected interferencemeasurements, the database comprising information regarding interferencelevels experienced by the network entity for LTE communication onchannels of the unlicensed band.
 15. The apparatus of claim 14, furthercomprising means for selecting and communicating on a selected channelof the unlicensed band to minimize the interference caused orexperienced by the network entity.
 16. An apparatus, comprising: atleast one radio frequency (RF) transceiver; at least one processorcoupled to the at least one RF transceiver and configured to: operate ina first mode using a first radio access technology (RAT1); collectinterference measurements for interference to or from at least onemobile device while in the first mode; switch to a second mode and usinga second radio access technology (RAT2); and use the interferencemeasurements from the first mode to minimize interference caused orexperienced by the network entity in the second mode; and a memorycoupled to the at least one processor for storing data.
 17. Theapparatus of claim 16, wherein the at least one processor is furtherconfigured to modify Reference Signal Received Power (RSRP)/ReferenceSignal Received Quality (RSRQ).
 18. The apparatus of claim 16, whereinthe at least one processor is further configured to build a databasefrom the collected interference measurements, the database comprisinginformation regarding interference levels experienced by the networkentity for Wi-Fi communication on channels of the unlicensed band. 19.The apparatus of claim 18, wherein the at least one processor is furtherconfigured to select and communicate on a selected channel of theunlicensed band to minimize the interference caused or experienced bythe network entity.
 20. A computer program product, comprising: anon-transitory computer-readable medium comprising code for causing acomputer to: operate in a first mode using a first radio accesstechnology (RAT1); collect interference measurements for interference toor from at least one mobile device while in the first mode; switch to asecond mode and using a second radio access technology (RAT2); and usethe interference measurements from the first mode to minimizeinterference caused or experienced by the network entity in the secondmode.
 21. The computer program product of claim 20, wherein thenon-transitory computer-readable medium further comprises code forcausing the computer to modify Reference Signal Received Power(RSRP)/Reference Signal Received Quality (RSRQ).
 22. The computerprogram product of claim 20, wherein the non-transitorycomputer-readable medium further comprises code for causing the computerto build a database from the collected interference measurements, thedatabase comprising information regarding interference levelsexperienced by the network entity for Wi-Fi communication on channels ofthe unlicensed band.
 23. The computer program product of claim 22,wherein the non-transitory computer-readable medium further comprisescode for causing the computer to select and communicate on a selectedchannel of the unlicensed band to minimize the interference caused orexperienced by the network entity.